The use of non-ionic surfactants with different Hydrophilic-Lipophilic Balance (HLB) and their effect on flow properties in palm oil biodiesel

The use of surfactants has been known to reduce the interfacial tension between the two fluids. Surfactants have Hydrophilic-Lipophilic Balance (HLB) values that vary depending on their function. Previously, the addition of the Sorbitan Monooleate (SMO) had succeeded in reducing the Cloud Point (CP) by 4.2°C and the Cold Filter Plugging Point (CFPP) by 2°C. In this research, two different types of nonionic surfactants were tried, named the Sorbitan Monolaurate (SML) and the Sorbitan Trioleate (STO), which have HLB values of 8.6 and 1.8, respectively. This research aims to prove whether these surfactants can improve the flow properties of palm oil biodiesel by reducing the interfacial tension. Each surfactant was varied in palm oil biodiesel with a content of 1 and 2% at room temperature (±27°C) for a month with every week observation. Then, it was tested using the flow properties parameters, which are the CP, Pour Point (PP), and CFPP. The FTIR analysis is also carried out to determine the interactions between MG and these surfactants. The addition of 1% SML caused escalation in the CP, PP, and CFPP by 3.2, 3.5, and 6°C, respectively. Meanwhile, the addition of 2% STO caused a reduction in the CP and PP by 0.5 and 1°C, respectively but the CFPP tended to be constant.